Return of the Black-footed Ferret

Mustella nigripes

Conata Basin is home to the largest population of one of North America’s most endangered animals: the black-footed ferret. Once common across the Great Plains, today this native species inhabits only about 2 percent of its original range.

These mainly nocturnal mammals live underground in prairie dog burrows and are quite playful and vocal. They measure 18 to 24 inches long and weigh less than three pounds. The ferret’s yellow-beige color and black markings on its face, feet and tail help it to blend in with its surroundings. It has short legs with large front paws and claws that are adept at digging.

Due to habitat fragmentation and the eradication of the species’ primary food source—prairie dogs—biologists feared the ferrets had gone extinct in the 1970s. Then, in 1981, a rancher’s dog in Wyoming brought home a ferret it had killed. This led to the discovery of a small number of ferrets nearby. When canine distemper, a disease fatal to ferrets, nearly wiped out this population, the remaining individuals were collected by the U.S. Fish and Wildlife Service and bred in captivity.

From only seven breeding ferrets, conservationists re-established their numbers and began releasing them into the wild. For the first time since the recovery program began, there are more ferrets in the wild—just under 500 adults—than in captivity. From 1996 to 1999, 147 black-footed ferrets were released in Conata Basin, an area where the species had existed historically. As of the 2007 field season, about 250 adult ferrets populate the Basin, more than in any of the other 12 reintroduction sites. On the grazing allotments associated with the recently-purchased Double Bar Seven Ranch, there are approximately 135 ferrets— roughly one-quarter of the known wild population. The Basin reintroduction program has remained free of devastating disease such as the sylvatic plague and has been so successful that it supplies animals for reintroduction programs elsewhere.

The black-footed ferret’s success in Conata Basin is largely due to the area’s 26,000 acres of prairie dog towns, one of the largest remaining complexes on the continent. Black-footed ferrets prey almost exclusively on prairie dogs and rely on their burrows for shelter and to raise their young. Black-tailed prairie dogs are a significant species in the Great Plains on which many other animals depend. Their extensive network of tunnels provides homes to burrowing owls, prairie rattlesnakes and numerous other species. They are a critical source of food for many predators, including ferruginous hawks, swift foxes and golden eagles.